With the release of OpenJDK 21, manufacturers are offering long-term support (LTS). However, this version has a lot more to offer besides that.
With 15 JEPs (JDK Enhancement Proposals), OpenJDK 21 brings forth a plethora of topics. It holds a host of interesting features for us Java developers. Some functionalities have been in the works for a while, such as Pattern Matching, Virtual Threads, Vector API, and Foreign Function & Memory API. While aspects like Pattern Matching and Virtual Threads have been finalized, others remain in Preview or Incubator mode. However, developers are particularly excited about new topics like String Templates, “Unnamed Classes and Instance Main Methods,” and Sequenced Collections.
Pattern Matching is now fully usable in production environments. It allows for matching existing structures with patterns to implement complex case distinctions efficiently and maintainably. This feature, developed under Project Amber for several years, has progressed from basic functions to more advanced ones like Record Patterns and Pattern Matching for switch. These advancements make the code more concise, readable, and less error-prone. Additionally, Virtual Threads are revolutionizing Java by allowing a significantly larger number of concurrent threads, leading to better CPU utilization. These threads will likely be embedded in frameworks like Spring and Quarkus, enhancing web application performance.
